code: def validate(self) -> None:
      assert self.keep in ["first", "last", False]
  
file_path: pygraphistry/graphistry/compute/predicates/categorical.py
imports: from typing import Any, TYPE_CHECKING
  from typing_extensions import Literal
  import pandas
  from .ASTPredicate import ASTPredicate
label_desc: Use image node_id 3 for calling the Duplicated obj's underlying member method code with example usage: obj.validate() without return types